This research will address the controversial topic of the extent that slabs at subduction zones extend into the lower mantle. The research will utilize data from the International Seismic Centre travel times, the Harvard Centroid Moment Tensor catalog, and waveform analysis techniques to map velocity structure and seismic strain rates at subduction zones throughout the world. The question of extent of slabs into the lower mantle is critical to models of convection within the mantle which is the ultimate driving force for plate tectonics.
